90421939 has 2 divisors, whose sum is σ = 90421940. Its totient is φ = 90421938.

The previous prime is 90421907. The next prime is 90421951. The reversal of 90421939 is 93912409.

It is a strong prime.

It is an emirp because it is prime and its reverse (93912409) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90421939 - 2⁵ = 90421907 is a prime.

It is a super-2 number, since 2×90421939² = 16352254105039442, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 90421898 and 90421907.

It is not a weakly prime, because it can be changed into another prime (90421039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45210969 + 45210970.

It is an arithmetic number, because the mean of its divisors is an integer number (45210970).

Almost surely, 2^90421939 is an apocalyptic number.

90421939 is a deficient number, since it is larger than the sum of its proper divisors (1).

90421939 is an equidigital number, since it uses as much as digits as its factorization.

90421939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 90421939 is about 9509.0451150470. The cubic root of 90421939 is about 448.8397087899.

The spelling of 90421939 in words is "ninety million, four hundred twenty-one thousand, nine hundred thirty-nine".